Effect of warm mix additives on asphalt cement, asphalt rubber and asphalt mixture quality and durability

本研究旨在探讨温拌沥青技术对沥青品质及耐久性能的影响。在过去的十年里，安大略省交通部(MTO)已经开始了几个提高可持续性的计划。最近推出的温拌沥青有助于在更低的温度(30-50摄氏度)下进行压实。去年，MTO放置了22万吨热混合料，预计这一数量在未来几年将大幅增加。使用沥青橡胶可以回收大量橡胶轮胎，并有可能显著提高生命周期成本。在支持方面，MTO已经使用橡胶碎屑改进剂进行了多次试验。安大略省轮胎管理局(OTS)和MTO现在承诺在2013年建造三个温拌沥青橡胶试验。热混合料带来的较低温度为沥青橡胶提供了几个特别可取的优势：减少排放、降低能源成本、便于长途运输以及季末铺路。然而，缺乏专门评估这些添加剂对质量和耐用性的影响的研究。我们将质量定义为沥青水泥抵抗车辙、疲劳、热裂和水分损害的能力。耐久性被定义为在较长的使用寿命内保持所需性能的能力。我们假设，各种添加剂(热混合料和橡胶)的质量和耐久性将会有明显的差异，这些差异尚未得到用户和生产商的认可。加拿大大部分地区的寒冷温度可能会产生不必要的早期痛苦，导致未来的成本，使在寒冷气候铺设中继续使用潜在有益的概念变得不可持续。研究结果将有助于沥青行业选择在长期成本和风险控制方面提供最大效益的温拌和沥青橡胶技术。该项目将在沥青科学和工程的最新方面培训一批研究生和本科生。与温拌添加剂与沥青水泥相互作用相关的发现也可能在石油加工等其他领域具有潜在的应用。

The proposed research is to investigate the effect of warm mix asphalt technologies on asphalt quality and durability. Over the past decade, the Ontario Ministry of Transportation (MTO) has embarked on several programs that improve sustainability. The recent introduction of warm mix asphalt facilitates compaction at much reduced temperatures (30C-50C). Last year MTO placed 220,000 tonnes of warm mix and this amount is expected to increase significantly in years to come. The use of asphalt rubber allows for the recycling of large quantities of rubber tires and has the potential to significantly improve lifecycle costs. In support, MTO has constructed numerous trials using crumb rubber modifier. The Ontario Tire Stewardship (OTS) and MTO are now committed to the construction of three warm mix asphalt rubber trials in 2013. The lower temperatures facilitated by warm mixes provide several advantages that are particularly desirable for asphalt rubber: reduced emissions, reduced energy costs, facilitation of longer haul distances, and late season paving. However, there is a dearth of studies that specifically assess the effect such additives have on quality and durability. We define quality as the ability of an asphalt cement to resist rutting, fatigue, thermal cracking, and moisture damage. Durability is defined as the ability to maintain desired properties over a long service life. We hypothesize that there will be pronounced quality and durability differences for the various additives (warm mix and rubber) that have yet to be recognized by users and producers alike. Cold temperatures in much of Canada could produce unwanted early distress resulting in future costs, making the continued use of potentially beneficial concepts in cold climate paving unsustainable. The research results will help the asphalt industry with the selection of warm mix and asphalt rubber technologies that provide the greatest benefit in terms of long term cost and risk control. The project will train a number of graduate and undergraduate students in the latest aspects of asphalt science and engineering. The findings related to the interaction of warm mix additives with the asphalt cement could also have potential applications in other areas such as petroleum processing.